<?xml version="1.0"?>
<?xml-stylesheet type="text/xsl" href="#stylesheet"?>
<!DOCTYPE root [
  <!ATTLIST xsl:stylesheet id ID #IMPLIED>
]>
<root>
<xsl:stylesheet id="stylesheet" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">
  <xsl:variable name="var"><p>a</p></xsl:variable>
  <xsl:template match="/"><xsl:copy-of select="$var" /></xsl:template>
</xsl:stylesheet>
</root>
